ISO 11551-2019 (2020) PDF

Full title and description

Optics and photonics — Lasers and laser-related equipment — Test method for absorptance of optical laser components. This International Standard defines calibrated, reproducible calorimetric procedures to determine the fraction of incident laser radiant flux that is converted to heat (absorptance) for optical components such as mirrors, lenses, windows and coatings.

Abstract

This standard specifies procedures and techniques for obtaining comparable values for the absorptance of optical laser components by measuring thermally converted absorbed energy. It covers preparation of test samples and measuring arrangements, characterization of the laser radiation, calibration of power and temperature signals, calibration of thermal response, background subtraction, procedures for continuous and pulsed irradiation, data-evaluation methods (including exponential and pulse methods) and required test report contents. Informative annexes discuss effects that change absorptance, signal distortions and an algorithm for parameterizing temperature data.

General information

• Status: Published.
• Publication date: Edition 3 published 2019 (corrected version January 2020).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 31.260 (Optoelectronics, lasers and photonics).
• Edition / version: Edition 3 (2019); corrected version 2020-01.
• Number of pages: 16 pages.

Key bibliographic and status details are reported on the ISO record and the corresponding EN (European) adoption.

Scope

Specifies a calorimetric test method to obtain comparable absorptance values for optical components exposed to laser radiation. The method reports absorptance as the ratio of radiant flux converted into heat and absorbed by the component to the incident radiant flux. It is intended for components where absorption is effectively converted to heat during the test; non‑thermal absorption processes are not detected by the procedure. The document defines sample preparation and environmental controls, beam characterization, calibration requirements and distinct procedures for continuous-wave and pulsed lasers.

Key topics and requirements

• Definitions and limits: absorptance limited to thermally converted absorption; relevant symbols and units.
• Sample preparation and handling: storage, cleaning, mounting and environment (including cleanliness classes where applicable).
• Laser characterization: beam parameters, spot size, stability and wavelength considerations for the test.
• Calibration procedures: calibration of optical power, temperature sensors, thermal response of sample/holder and background signal measurement/subtraction.
• Test procedures: methods for continuous-wave and pulsed irradiation, irradiation durations and limits to avoid changes in absorptance during the test.
• Data evaluation: drift elimination techniques; exponential method and pulse method to extract absorptance from temperature–time data; parameterization algorithm for temperature data.
• Reporting requirements: detailed information to include in test reports to ensure reproducibility and comparability.
• Informative annexes: effects that change absorptance, influence of signal distortions, and algorithmic guidance for data processing.

These technical requirements and informative annexes provide the practical steps and cautions needed for reliable calorimetric absorptance measurement.

Typical use and users

Used by optical component manufacturers, test laboratories, research groups and quality/acceptance test teams dealing with laser systems. Typical applications include characterizing coatings and substrates for high-power laser systems, estimating heat load from laser irradiation, acceptance testing of optics, supplier comparison, and informing thermal-management design decisions in laser optics and systems.

Related standards

Contains normative or related references that commonly accompany absorptance testing, including ISO 11145 (vocabulary and symbols for lasers and laser‑related equipment), ISO 80000‑7 (units and quantities for light and radiation) and standards addressing cleanroom classification where sample cleanliness is relevant (for example ISO 14644‑1). The 2019 edition replaces earlier editions such as ISO 11551:2003; revision activity (ISO/DIS 11551) has been noted in committee work.

Keywords

absorptance; absorptivity; calorimetric test; laser optics; optical components; laser-induced heating; calibration; continuous-wave; pulsed lasers; exponential method; pulse method; thermal response; optical coatings.

FAQ

Q: What is this standard?

A: ISO 11551:2019 (corrected 2020‑01) is an international test standard that defines calorimetric methods to measure the absorptance of optical laser components — i.e., the fraction of incident laser energy converted to heat in the component.

Q: What does it cover?

A: It covers sample preparation and handling, requirements for the laser radiation and measuring arrangement, calibration of power and temperature signals, calibration of thermal response, procedures for continuous and pulsed irradiation, data-evaluation methods (including exponential and pulse methods), reporting requirements and informative annexes on effects and distortions.

Q: Who typically uses it?

A: Optical-component manufacturers, independent test laboratories, research institutions, and system integrators who need reproducible absorptance data for component specification, quality control, or thermal-design assessment.

Q: Is it current or superseded?

A: The edition in force is the third edition published in 2019 with a corrected version issued January 2020. The standard is maintained by ISO technical committees and has been noted for future revision activity; users should check their national standards body or ISO records for the latest status before relying on it for regulatory or procurement decisions.

Q: Is it part of a series?

A: It sits within ISO technical work on optics and photonics (ISO/TC 172/SC 9) and is related to other laser/optics standards such as ISO 11145 (vocabulary/symbols) and standards covering units and quantities (ISO 80000‑7). The document also follows the numbering and revision tradition of earlier ISO 11551 editions (for example 2003 edition).

Q: What are the key keywords?

A: absorptance, absorptivity, calorimetric measurement, laser optics, optical coatings, thermal response, calibration, continuous-wave, pulsed lasers.